1. Field of the Invention
This invention relates to an insect trap, in particular to a pitfall fall cone trap for insects in grain and other granular bulk materials.
2. Discussion of Prior Art
There are various types of insect trap currently in use. For example UK Patent 1,598,010 describes a trap in the form of a rectangular box having apertures which allow entry of the insects containing trays holding bait, and which has a space wherein insects can be trapped or killed by the presence of, for example, paraffin. Whilst this trap could be used with a granular bulk material it would have to be buried therein to leave its top (in which are the apertures) level with the material surfaces. This would be a work intensive process, in view of the shape of the trap.
In another form of trap, described in U.S. Pat. No. 4,581,845 a shallow pitfall chamber containing oil is positioned in a wafer formation formed by folding up a segmented sheet of material which is plain on one side and corrugated on the other side. Some of the segments have apertures therein to hold the pitfall chamber, and a top segment covers the chamber. Insects gain access to the trap (which may hold a lure) through the channels formed by the corrugations, and eventually reach the pitfall. This type of trap can be positioned on top of a bulk granular material, but is unsuitable for use within the bulk, where the channels would be blocked by grains.
Another type of trap is a surface beaker type which is unlidded, whilst yet another is a rod-like insect probe trap which may be inserted into the grain. The former of these can only be used at the surface and the latter only below the surface of the grain and neither can operate in place of the other.